Recovery of by-products in mercury fulminate manufacture



Patented June v19, 1923.. V

UNITED STATESPATENT OFFICE.

ROBERT C. MORAN, OF RIDLEY PARK, PENNSYLVANIA, ASSIGNOR TO E, I, DU PONTDE NEMOURS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELA-WARE.

RECOVERY OF BY-PRODUCTS IN MERCURY FULMINATE MANUFACTURE.

No Drawing. Application filed June 17, 1920. Serial No. 389,729.

To allwhom it may concern: and alcohol, both free and combined, can beBe it known that I, ROBERT C. MORAN, a made from the condensate by asimpler procitizen of the United States, and a resident cedure, and onerequiring much less time, 55

of Ridley Park, in the county of Delaware manipulation, etc., than thatdescribed in and State of Pennsylvania, have invented a my abovementioned application. This imcertain new and useful Recovery ofByproved procedure consists essentially in Products in Mercury FulminateManufactreating the condensate with an alkali-formture, of which thefollowing is a specificaing metal hydroxide, while cooling it, (pref- 60tion. erably to below 0.), to saponify the This invention relates to therecovery of ethyl formate; 'separating by decantation This condensatetends to separate into two To 75 lbs. of condensate in a closed high-''35 aration of the several constituents could be geneous solution by theelimination of the by-products, chiefly nitrites, formates, .and theresultingethyl nitrite-alcohol layer from ethyl alcohol, from the liquorobtained by the water layer containing the formate of the condensationof the vapors evolved in the alkali-forming metal; then hydrolyzing themanufacture of mercury fulminate, the ethyl-nitrite by heating the ethylnitrite- 15 (C N .O) Hg. alcohol mixture in the presence of water and Inthe manufacture of fulminate of meran alkali-forming metal hydroxide,prefercury by the interaction of alcohol, nitric acid ably at atemperature above 0.; and and mercury, a vigorous reaction takes placefinally separating the alcohol from the re- 70 during the course ofwhich there is evolved sulting metal nitrite and from at least a 20 aquantity of vapors equivalent in Weight large proportion of the water bydistillation. to approximately one-half of that of the raw It isdesirable to add sufficient hydroxide, materials used. lNhen efficientlycondensed, preferably an alkali-metal hydroxide, to these vapors yield aliquor (which will be convert all of the ethyl nitrite present to adesignated condensate hereinafter) of the metal nitrite and ethylalcohol. A 30% 25 following approximate composition: 35% aqueous sodiumhydroxide solution is a conethyl nitrite, 16% ethyl formate, 30% ethylvenient form in which to add the hydroxide alcohol, 10% water, 5%aldehyde; the reto the ethyl nitrite-alcohol mixture. mainder being madeup of ethyl acetate, My invention may be illustrated by the ethylnitrate, nitric and nitrous acids, etc. following example:

layers, the lower one being chiefly composed pressure autoclave which isjacketed for of Water. brine-cooling and steam-heating and is pro Thecomplex character of the above-devided with agitation apparatus, isadded 12 scribed mixture would indicate that the seplbs. of alcohol inorder to obtain a homoefi'ected, if at all, only after thedeterminawater layer usually present in the condention of very preciseconditions of treatment. sate. Under brine-cooling and agitation, theHeretofore the only constituent of this mix requisite amount (about 30lbs.) of a 30% ture which has been recovered is the alcohol. aqueoussolution of sodium hydroxide, to 40 In my application Serial N 0. 386337filed saponify the ethyl formate and render the June 3, 1920, I have setforth a process of solution neutral, is added to the condensaterecovering several by-products from the charge by means of anunder-surface feed above described condensate, said process, at such arate that the temperature of the briefly stated, consisting inseparating the reaction mixture does not exceed 15 C. 45 ethyl nitritefrom the rest of the condensate (59 F.). The requisite amount of sodiumby a carefully controlled distillation, then hydroxide may be determinedby a titration hydrolyzing separately the ethyl nitrite in in the coldof a sample of the homo eneous the distillate and the ethyl formate inthe condensate with standard alkali. The residue, and finally separatingby distillasodium hydroxide is used in the form of a 50 tion the ethylalcohol thus formed. concentrated aqueous solution in order that Onfurther investigation, I have now disaqueous solution of sodium formatesubsecovered that the recovery of nitrite, formate, quently formed inthe reaction mixture shall be of such concentration as to reduce to aminimum the solubility value of alcohol therein.

After the complete addition of the concentrated aqueous causticsolution, which usually requires about one hour with efficientbrine-cooling, the agitation is stopped to allow the reaction mixture toseparate into a lower layer of aqueous sodium formate containing anegligible amount of alcohol and an upper layer of alcohol and ethylnitrite.

The lower aqueous sodium for-mate layer is removed by gravity, filteredand evaporated to dryness. The crude product analyzes about 70-75%actual sodium formate. The crude product amounts to about 14 lbs.

The ethyl nitrite content of the alcoholice'thyl nitrite solutionremaining in the autoclave is then determined. 7 lbs. of water is thenadded to the autoclave charge so that, following the addition of therequisite amount of a aqueous sodium hydroxide solution in order tosaponify the ethyl nitrite, a homogeneous reaction "solution will beobtained. 4

The saponification is then carried out by gradually raising thetemperature of the .autoclave charge to about 100C. (212 F.),

corresponding to a pressure of about lbs. per sq. in. Within two hoursthe saponification is completed under these conditions. The timerequired for the saponification may be reduced by .maintaining a highertemperature and pressure.

The alcohol is then distilled directly from the autoclave using adephlegmator so as to return the water to the autoclave. The resultingdistillate comprises the alcohol originally present in the condensatetogether with that formed by the saponification of the ethyl formate andthe ethyl nitrite. A yield of about 41 lbs. of alcohol of strength byweight may be readily obtained.

Following the distillation of the alcohol there is suflicient waterpresent in the autoclave to completely dissolve the sodium nitriteproduct. The sodium nitrite solution is drawn ofi", filtered andevaporated to dry ness. The crude sodium nitrite product, amounting toabout 21 lbs., analyzes 70-80% actual sodium nitrite.

Although my new process has been described above in great detail, itwill be understood that the conditions of operation and the proportionsof reagents may be varied considerably without departingfrom the spiritand scope of my invention.

I claim w 1. The process of recovering valuable products from a mixturecontaining ethyl nitrite, ethyl formate, ethyl alcohol, and water, whichcomprises .saponifying the ethyl formate at a temperature sufiicientlylow to avoid substantial hydrolysis of ethyl nitrite, separating theresulting metal formate from the alcohol and the ethyl nitrite, and thenheating the ethyl nitrite in the presence of alcohol and a hydrolyzingagent until the hydrolysis of the ethyl nitrite is substantiallycomplete.

2. The process of recovering valuable products from a mixture containingethyl nitrite, ethyl for-mate, ethyl alcohol, and

'water, which comprises saponifying the ethyl for-mute while cooling thesolution, separating the resulting metal for-mate 1n the form of a watersolution from the alcoholand the ethyl nitrite, then heating the*nitrite, ethyl formate, ethyl alcohol, and

water, which comprises adding an aqueous alkali-metal hydroxide solutionto the mixture to saponify the ethyl formate, while maintaining themixture at a temperature sufliciently low to avoid substantialhydrolysis of ethyl nitrite, allowing the mass to segregate into twolayers. one composed mainly of alkali-metal formate and Water, and theother of ethyl nitrite and alcohol, separating said layers, and treatingthe ethyl nitrite-alcohol mixture with a hydrolyzing agent at a hightemperature until hydrolysis of the ethyl nitrite is effected.

' 4t. The process of recovering valuable products from a mixturecontaining ethyl.

nitrite, ethyl formate, ethyl alcohol, and water, which comprises addingan aqueous alkali-metal hydroxide solution to the mixture to saponifythe ethyl formate, while maintaining the mixture at a temperaturesufficiently low to avoid substantial hydrolysis of ethyl nitrite,allowing the mass to segregate into two layers, one composed mainly ofalkali-metal formats and water,

and the other of ethyl nitrite and alcohol, separating said layers, andheating the ethyl nitrite-alcohol mixture with an aqueous solution of analkali-metafi hydroxide at a temperature above 70 C. to hydrolyze theethyl nitrite.

5. The process of recovering valuable products from a mixture containingethyl nitrite, ethyl formate, ethyl alcohol, and water, which comprisesadding an aqueous alkali-metal hydroxide solution to the mixture tosaponify the ethyl formate, While maintaining the mixture at atemperature sufficiently low to avoid substantial hydrolysis of ethylnitrite, allowing the mass to segregate into two layers, one composed;mainly of alkali-metal formate and water, and the other of ethyl nitriteand alcohol,

recaeio separating said layers, and heating the ethyl nitrite-alcoholmixture with an aqueous al kali-metal hydroxide solution at atemperature of about 100 C. and under pressure until hydrolysis of theethyl nitrite is sub stantially complete.

6. The process of recovering valuable products from a mixture containingethyl nitrite, ethyl formats, ethyl alcohol, and water, which comprisesadding suflficient alcohol to said mixture to prevent formation of awater layer, gradually adding an aqueous sodium hyroxide solutlon to themixture while agitating it and while maintaining it at a temperature notexceeding 15 (1, until the ethyl format/e has been converted into ethylalcohol and sodium formate, allowing the reaction mixture to separateinto a lower layer of water and sodium formats, and an upper layer ofalcohol and ethyl nitrite, removing the lower layer, adding an aqueoussodium hydroxide solution to the alcohol and ethyl nitrite, heating theresulting mixture under pressure to a temperature above 70 C. until theethyl nitrite is hydrolyzed, and then separating the alcohol from waterand sodium nitrite by distillation.

7. In the process of recovering valuable products from a mixturecomposed mainly of ethyl nitrite, ethyl formate, ethyl alcohol, andwater, the ste s which comprise saponi tying the ethyl tormate at atemperature suificiently low to avoid' substantial hydrolysis of ethylnitrite, and then separating the resulting metal formate in the form ofa water solution by decantation.

8. In the process of recovering valuable products from a mixturecomposed mainl of ethyl nitrite, ethyl formate, ethyl alcoho drolysis ofethyl nitrite, separating the resu ting metal formats in the form ofawater solu tion by decant'ation, and then heating the remaining alcoholand ethyl nitrite with an aqueous alkali-forming metal hydroxidesolution at a high temperature to hydrolyze the ethyl nitrite.

9. The recess of treatin the liquor, containing et yl formats, ethynitrite, and alcohol, obtained by condensation of vapors evolved in theordinary manufacture of mercury fulminate, which comprises subjectingsaid liquor to the action of an alkali-forming metal hydroxide until theethyl formate is saponified, while maintaining the temperature below 20C. to avoid substantial hydrolysis of ethyl nitrite.

10. The process of treating the liquor, containin ethyl formats, ethylnitrite, and alcohol, 0 tained by condensation of vapors evolved in theordinary manufacture of mercury Tulminate, which comprises graduallyadding to said liquor, while stirring and coolin the same to atemperature substantially low 70 (3., suficient alkalimetal hydroxidesolution to saponify the ethyl formate, allowing the mixture to separateinto two layers, and then removing one layer from the other.

In testimony whereof ll afiix m si ature.

ROBERT C. WOAN.

